The process of purification of Cd2+ ions from model wastewater by the slag of electric furnace steelmaking process was investigated; the kinetic regularities of the sorption process were studied. During the work on the basis of experimental data taking into account the mass of the additive, the temperature of the reaction mixture, the duration of the contact, a mathematical simulation of the reagent-sorption purification process was carried out. Titrimetric, spectrophotometric, atomic absorption methods of investigation were used in the work, chemical composition of slag was established. The article may be of interest to specialists in the field of obtaining new adsorbents using waste products.